Second order active filter

Table of Contents

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details <https://www.gnu.org/licenses/>.

This code was developed by Miodrag Bolic for the book PERVASIVE CARDIAC AND RESPIRATORY MONITORING DEVICES: https://github.com/Health-Devices/CARDIAC-RESPIRATORY-MONITORING

% Changing the path from main_folder to a particular chapter
main_path=fileparts(which('Main_Content.mlx'));
if ~isempty(main_path)
    %addpath(append(main_path,'/Chapter2'))
    cd (append(main_path,'/Chapter3/RC Circuit and Filters'))
    addpath(append(main_path,'/Service'))
end
SAVE_FLAG=1; % saving the figures in a file

Introduction

% Exact linearization of the Simulink model filter_80hz
% Specify the model name
model = 'SallenKeyFilter';

Specify the analysis I/Os

Get the analysis I/Os from the model

io = getlinio(model);

Specify the operating point

Use the model initial condition

op = operpoint(model);

Linearize the model

sys = linearize(model,io,op);

Plot the resulting linearization

h = bodeplot(sys);

setoptions(h,'FreqUnits','Hz','PhaseVisible','on');

hold on

p = bodeoptions('cstprefs');

p.FreqUnits = 'Hz';

p.Grid = 'on';

p.Xlim{1}(1)=10^-1;

p.Xlim{1}(2)=10^3;

p.PhaseWrapping='on';

bodeplot(sys,p)

exportgraphics(gcf,"Fig3.19.jpg", 'Resolution',600)